The present invention relates in general to new, improved and more efficient apparatus for producing domestic hot water (hereinafter sometimes "DHW"), and more particularly to an ancillary heat pump (hereinafter sometimes "AHP") system for such purpose.
Experts within the electric utility industry have determined that the 1990 Federal Clean Air Act and other regulatory action may necessitate replacement of resistance electric heat water heating technology, due to the primary energy intensiveness of the operation of such technology. Some public utility commissions have mandated that the electric utilities replace those residential electric hot water heaters utilizing fossil fuel-fired heaters. Thus, the potential loss of the controllable load of over 20,000,000 residential electric hot water heaters has been of major concern for the utilities. In addition, these energy-related factors have presented utility companies with major marketing problems in regard to new residential construction.
The above problems which are principally related to large levels of primary energy consumption have engendered the search for more energy efficient means of producing domestic hot water. Presently available systems for producing domestic hot water, include, inter alia, integrated and combined space conditioning and water heating heat pump apparatus, self-contained heat pump water heaters, desuperheaters and full condensers (some of which are provided as add-ons to condensing units), heat pipe dehumidification apparatus, and similarly related apparatus.
However, each of these presently available prior art methodologies has associated therewith one or more serious application and/or cost effectiveness problems. Some of the problems associated with the prior art are:
1. the necessity for protecting potable water lines from freezing with an add-on reclaim heat exchanger mounted within an outdoor (condensing) unit; PA0 2. the major additional cost of providing a module with the compressor located indoors; PA0 3. field modification of the refrigerant piping system; and PA0 4. installation cost and application problems associated with dedicated heat pump hot water heaters.
In view of the above difficulties, defects and deficiencies with prior art domestic hot water production systems, it is a material object of the present invention to reduce significantly each of the above and other problems associated therewith.
It is a further object of the present invention to provide an ancillary heat pump system for production of domestic hot water wherein a preferably small and self-contained heat pump having a co-axial heat exchanger and compressor is disposed, in one preferred embodiment, with a heat exchanger coil thereof directly in the return air stream of a heat pump or of a heating and air conditioning system.
It is also an object of the present invention to provide means for injecting the associated cooling effect hereof directly into an accompanying heating and air conditioning system, rather than merely "dumping" such associated cooling effect into the space around the heater tank.
It is also a further object of the present invention to provide apparatus wherein there is no necessity to pipe potable water into an outdoor environment, or, as an alternative, to repipe extensively the refrigeration circuit of the condensing unit to an indoor heat exchanger location, but rather to keep the HVAC and hot water system refrigeration circuits totally isolated, so that there is no risk of water contaminating the HVAC refrigeration system in the event of a heat exchanger failure.
It is a yet further object of the present invention to provide hot water efficiently during the heating season regardless of the type of space heating fuel being used.
These and other objects of the ancillary heat pump apparatus for providing domestic hot water of the present invention will become more apparent to those skilled in the art upon review of the following summary of the invention, brief description of the drawing, detailed description of preferred embodiments, appended claims and accompanying drawing.